Application of randomized algorithm in key frames extraction

With the application of multimedia information, a large amount of video information comes forth, how to retrieval the information required from the vast amount of data is vital. Content-based Video Retrieval is one of the leading methods to get the needed information from the vast amount of video data. Technology to extract key frames, which is an important part of content-based video retrieval, was studied carefully. In the compressed domain environment, firstly divide the two frames to be compared into sub-blocks, and then use randomized algorithm to select a subset of the divided sub-blocks to calculate similarity, and then to select key frames. The method can be guaranteed to meet the inter-frame similarity calculation under a certain precision, significantly reducing the number of sub-blocks needed to compare, thereby enhancing operational efficiency of the algorithm, and experimental results proved to be better.